trace-cmd reset [OPTIONS]
The trace-cmd(1) reset command turns off all tracing of Ftrace. This will bring back the performance of the system before tracing was enabled. This is necessary since trace-cmd-record(1), trace-cmd-stop(1) and trace-cmd-extract(1) do not disable the tracer, event after the data has been pulled from the buffers. The rational is that the user may want to manually enable the tracer with the Ftrace pseudo file system, or examine other parts of Ftrace to see what trace-cmd did. After the reset command happens, the data in the ring buffer, and the options that were used are all lost.
When the kernel boots, the Ftrace ring buffer is of a minimal size (3 pages per CPU). The first time the tracer is used, the ring buffer size expands to what it was set for (default 1.4 Megs per CPU).
If no more tracing is to be done, this option allows you to shrink the ring buffer down to free up available memory.
trace-cmd reset -b 1
- If the kernel supports multiple buffers, this will reset the trace for only the given buffer. It does not affect any other buffer. This may be used multiple times to specify different buffers. The top level buffer will not be reset if this option is given (unless the -t option is also supplied).
- Delete the previously specified buffer instance that was specified by the -B option. It is invalid to use with -t as the top level instance can not be deleted.
- Resets the top level instance buffer. Without the -B option this is the same as the default. But if -B is used, this is required if the top level instance buffer should also be reset.
Written by Steven Rostedt, <m[blue][email protected]m>
Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted under the terms of the GNU Public License (GPL).